PLCs evaluation/comparison

Hi fellows,

I’ve been asked to evaluate two or more different brands of PLCs in order to make a decision in which one will be the best suitable to undertake the new automation projects in the company.
(Keep in mind that the automation level is low or very old technology)

I immediately thought about A/B and Siemens.
You can say that the process level is not complex, mostly data acquisition, low number of I/O, simple control loops and GUI displaying but the process is mobile (mounted in trucks trailers) and segregated (several units at the time in the same location with the need of interchange information but each unit will have its own PLC performing local control and receiving set point from a central control room).


I would like to know what your thoughts about those two brands are in terms of:


-Hardware robustness (remember the equipment will be mounted in trucks in a harsh mobile environment)

-Networking: easiness to set up, to maintain, throughput, reliability, etc.

-Tech support.

-Versatility to configure/training for personnel, programming.

-Economics (price).

-Any other topic you consider worth to mention.

Also if there is any other brand out there that you may consider worth to evaluate will be welcome.

Best regards and thanks in advance for your quotes.

DELGADO

As a standalone, the S5/S7 family cannot be beat. Siemens is a programmer's PLC. Where Siemens falls flat is on its networking capabilities.

The A-B, especially Contrologix family, is far superior in its networking capabilities. Rockwell have finally got their act together with the PV+ family.

For support, if you have internet access, forums such as this are great for getting support. Rockwell used to have a user forum, but that has been shutdown. Their knowledge database is quite informative and quite straight forward to navigate.
The Siemens Web support seems very complex to navigate through

If it comes to phone only support, Rockwell beats Siemens hands down. Only drawback, you have to be 'in support' to get support from Rockwell. Otherwise, warranty is an option you need to purchase.

I recall that the S5 product had a marine rating meaning that they could be used on sea going vessels. I don't know if Rockwell have such a rating, but I do have a family member who works on the tar sands in Northern Alberta and they use SLCs and Micrologix PLCs on the mobile earth movers.

Ian

Thanks Ian quite valuable quote

The vast majority of AB's automation products have an ABS marine rating.

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This is a rare occasion indeed, where I support AB. AB is difficult to learn, compare to the brands that I normally use.

Siemens is near impossible.

AB, I consider to be the most over-priced, and I an not a fan of paying for support, but I think they would be the best bargain here.

Funny, I have been called to consider factory positions from both companies this year. While I am in contention for two postions currently and I AM starting to work at a third position for one of these two compaies on Monday, I would still go with those other guys from Milwaukee.

Siemens has "outdoor" versions of many of its models which are more robust and operate over a wider temperature range than the standard models. Have a word with your Siemens rep, he should be able to help you out.

BTW, since the US Navy has recently outfitted one of it's aircraft carriers using S7 equipment, I guess they must also have a marine version!